Whoa! Heck yea there is. Call Brumble Bikes and ask Amos if there is a group ride out of the shop. Great guy, legendary Cat I, and he doesn't have an ego. As for routes, yea there are a ton. Go by the water, go to North Stonington and climb hills - it's all over. There is also a 7am group ride out of Mystic on Saturday, but those guys like to do the world championship thing, but if you let them know you're not form around you will be cool.
The area is awesome for riding.